Skinflint has variable dejection (6)
I believe the answer is:
misery
'dejection' is the definition.
(thesaurus)
'skinflint has variable' is the wordplay.
'skinflint' becomes 'miser' (synonyms).
'has' is a charade indicator (letters next to each other).
'variable' becomes 'y' (algebra).
'miser'+'y'='MISERY'
(Other definitions for misery that I've seen before include "Party-pooper" , "Great distress or discomfort" , "Wretched unhappiness" , "Wretched state" , "Great suffering" .)